Artificial teeth and method of making same



Feb. 24, 1931. c. A. WALSH 1,794,129

ARTIFICIAL TEETH AND METHOD OF MAKING SAME Filed April 24, 1929 T ivezzaz' M (Mt/M Patented Feb. 24, 1931 UNETEE STATES CARLIN A. WALSH, OF CAMBRIDGE, MASSACHUSETTS ARTIFICIAL TEETH AND METHOD OF MAKING Application filed April 24,

The present invention relates to artificial teeth, and to a novel and improved method of manufacturing the same.

In important object of the invention is the provision of an artificial tooth in which the entire body portion is composed of porcelain, enamel or other ceramic material.

Another important object of the invention is the elimination of all metal, such as backing plates, interlocking tongue and socket members, uniting elements, and other devices at present in use. The only metal retained in my novel tooth is the pivot post or pin, which is preferably composed of platinum and which will cause no visible discoloration. Prior artificial teeth which embodied metallic portions were subject to discol oration, which was distasteful to the wearer and unsightly in appearance. My present invention obviates and eliminates this disadvantage and difficulty and enables the production of artificial teeth which will be uniform in shade and color, and will present, to all intents and purposes, the appearance of natural teeth.

Another feature of the invention resides in the fact that by my invention two or more teeth may be joined firmly and integrally together Without the use of any metallic connecting means. This is also an important advantage and results in a more sanitary, stronger tooth construction.

In carrying out my present invention I provide a core of ceramic material, having a pivot post or pin embedded therein. These cores may be made of different standard sizes and may be supplied from the manufacturer to the dentists in sets of said sizes. This core will preferably have a complete gingival margin and the said core may be entirely or partially baked, depending upon the circumstances of future use.

When it is desired to replace a tooth, the

dentist will prepare the root, and the core and pivot post will be either permanently or temporarily attached to said root. Thereupon the dentist will mix a quantity of porcelain, of desired shade to match the adjoin ing teeth, and will then apply, over the core, a matrix, preferably of platinum and of rela- 1929. Serial No. 357,746.

After the tooth is thus constructed, the

matrix and the built up shell will be removed, and will be baked, preferably While the matrix remains in the shell, to retain the shape thereof. The matrix will have a fusing point several hundred degrees higher than the porcelain shell, and will prevent distortion of the shell during baking.

Several variations of this basic idea are feasible. For example, to accomplish the best possible result, the cores would be supplied only partially baked. Thus when the shell is built up over the matrix and is of the desired shade, the exposed portion of the core may also be stained the proper shade, and the entire tooth baked as a unit, thus assuring uniformity of shade throughout the entire tooth.

A less expensive method, for the patient, will be to have the core and shell provided ready for installation, entirely baked, and merely requiring cementing and grinding to complete the installation. F or a slightly more expensive installation, the core and shell could be Then, after application and grinding to desired size, the shell and the exposed portion of the core could be stained to desired shade, and baking of the portions completed.

In these latter variations the matrix would not be requisite, said matrix only being necessary when the shell of the tooth is builtup thereto to produce the best possible results.

It frequently happens thata patient will provided each partially baked.

have two or more adjoining teeth missing,

with but a single root. A further and important feature of the present invention, therefore, resides in the fact that I am enabled to construct a tooth as described above, and then to integrally join the second tooth with said first tooth in such a manner that both teeth will be entirely constructed of porcelain or other ceramic material. The advantages of such a denture will be instantly apparent to those skilled in the art and will be appreciated by patients, as well.

In carrying out this phase of the invention, I provide an adjoining tooth composed entirely of porcelain, and having a substantlal retention cavity in the lingual surface thereof. Vvhen completing the shell of the pivot tooth, as above described, the plastic porcelain is continued from one side, toward the rear thereof, into said retention cavity, and is thoroughly packed therein. The two joined teeth are then ba red, and thus present a fixed unit of two teeth. This step of the invention can be repeated with a tooth on either or both sides of the pivot tooth, and will result in a strong, rigid, sanitary structure, with no cracks, metallic unions or backing plates or other objectionable features.

As a further step of my invention,I may provide two or more teeth, constructed entirely of porcelain and eachhaving cooperating retention cavities therein. To one of these teeth I will apply a pivot post and then pack both retention cavities with a continu ous mass of plastic porcelain, subsequent to which the united teeth will be baked, with the pivot post firmly united with one of said teeth.

This will provide an inexpensive, rugged, satisfactory installation. These teeth, with the retention cavities therein, may be initially prepared ither entirely or partially baked, enabling the dentist to stain the same or not, as desired. r

The above and other objects and features of the invention, details of construction, con hinat-ions of parts and advantages, will be hereinafter morefully pointed out, described and claimed.

Referring to the d swings, illustrating a preferred embodiment of the invention,

1 is a front elevation of a combined core and pivot post;

Fig. 2 is a side elevation of said core and post;

Fig. 3 is a side elevation of a preferred form of matrix; I

Fig. l is a side elevation of the core with matrix applied,

Fig. 5 is a side elevation illustrating the tooth after the shell of plastic porcelain has been built on said matrix;

Fig. 6 is a front elevation of Fig. 5;

Fig. 7 is a vertical medial sectional view of the matrix and shell after removal for baking;

Fig. 8 is a side elevation of the completed tooth, with the shell assembled and cemented to the core;

Fig. 9 is a side elevation of a tooth adapted to be joined to the tooth of Figs. 1 to 8 inclusive;

Fig. 10 is a top plan View of the tooth of Fig. 9 assembled with the tooth of Fig. 8;

Fig. 11 is a rear elevation of the teeth of Fig. 10

the tooth of Fig.12 is a rear elevation of a pair of teeth constructed according to a slight modification of my invention; and

Fig. 13 is a side elevation of the unit illustrated in Fig. 12.

Referring now to the drawings for a particular description of the invention, it will be appreciated that while I have illustrated my invention as applied to incisors, that the same is equally applicable to bicuspids or molars, or any of the upper or lower teeth.

As illustrated in Figs. 1 to 8 inclusive, my novel invention and process are carried out as follows:

I place a mass of plastic porcelain or other ceramic material over the headed end 6 of a pivot pin 5, and mold said mass to provide a core 1 closely simulating a natural tooth root which has been conditioned to receive a jacket crown. That is to say, the core 1 when molded to the desired shape has a full gingival portion 2 beyond which the outeror free end of the pivot pin 5 extends, this core including the labial and lingual face portions 3 and 4, respectively, of suitable extent or area, outwardly of which the body portion of the core is of reduced sectional area, whereby a shoulder is formed at the junction of the body portion with the gingival portion. I then bake this'core, preferably but not necessarily staining the core to the shade desired before the baking is completed. Thereafter I provide a matrix I, preferably of platinum and of relatively thin gauge, to fit the body portion of the core; i. e., to fit the portion of the Core which is disposed outwardly of the gingival portion 2, and I apply this matrix over said body portion. I then build a shell 8 of plastic porcelain or other ceramic material over the matrix, and shape said shell for cooperation with the labial and lingual face portions 3 and 4: of the core, to simulate a natural tooth,

making due allowance for shrinkage of the shell during baking there-of. I then remove the shell with the matrix therein from the core and, with the matrix remaining therein, bake the shell, preferably but not necessarily staining the shell to the shade desired before the baking thereof is completed. I then remove the matrix from the shell and thereafter apply the shell to the core, and secure the same thereto by an adhesive binder or in any other suitable manner. The result is that the shell cooperates with the core to simulate a complete natural tooth. That is to say, the inner end of the shell abuts the shoulder at the outer end of the gingival portion 2 of the core, and the outer and inner faces 9 and 10 of the shell form, in effect, flush continuations of the labial and lingual faces 3 and 4, respectively, of the core.

r The cores 1, each with a pivot pin embedded therein, preferably are provided as stock articles to be mounted in the mouth and to have the shells 8 built thereon in the manner heretofore described to suit individual requirements. However, the shells 8 may also be provided as stock articles to be selectively applied to the cores, in which event a stock shell selected for use in any particular instance, and after having been applied to the core, may be ground to desired finished size and shape.

Thus the patient will have the advantage of having a tooth constructed entirely of porcelain, built in said patients mouth to desired shape, contour and shade, with no metal therein except for the pivot post. There will thus be no discoloration of the tooth resulting from the presence of metallic parts therein, and the entire tootn structure will be firm, strong and sanitary, with no joints therein except between the top of the shell 8 and the edge of the exposed portions of the core 1. These advantages will be appreciated by those skilled in the art, as well as by the wearers thereof.

In Figs. 9, 10 and 11 I have illustrated a further step in my invention, wherein an abutting tooth is affixed or united to my novel pivot tooth. This form of denture will be found desirable where a patient has a missing tooth with no root to which a pivot tooth may be anchored. In practising this stage of the A invention, I provide a tooth 15 having a full gingival margin 16 and a full labial face 17. At the rear of the tooth are provided partial lingual faces 18, 18, a ret ntion cavity 19 being pro *ided as clearly illustrated in Fig. 9. This retention cavity is of substantial size, having a wide opening at the side, as is clearly apparent fr m a view of the drawings. The tooth 15 also has an incisal edge 21, unbroken throughout its entire extent.

In order to unite the tooth 15 with the tooth of Figs. 1 to 8 inclusive, the dentist will select a tooth 15 to match up with adjoining teeth, grinding same to finished shape if de sired. Preferably this tooth 15 will be furnished only partially baked, in order to allow for shrinkage thereof when subjected to additional baking and in order that the dentist will be enabled to stain the same to desired color to match up with the pivot tooth and adjoining teeth, although said teeth 15 may be furnished completely baked if desired. Then, as the dentist completes building up the shell 8 of the pivot tooth, he will extend the plastic porcelain, as illustrated at 20, into the cavity 19 in the tooth 15, packing the same firmly into said retention, the plastic porcelain thus forming a complete bridge between the two teeth. After the teeth are matched and otherwise completed, they will be re moved and baked as a unit, thus solidifying both of said teeth into one homogeneous mass with a strong, firm, permanent bond therebetween of sufficient size and strength to insure against fracture. The shell 8, with its adjoining teeth 15, will then be cemented onto the core 1, and the teeth will be complete and ready for'service immediately upon setting and hardenin ,of the cement.

When the p astic porcelain has been tamped into the retention cavity 19 and smoothed ofi, it will complete the lingual surface 18 of the tooth 15. structed entirely of porcelain, excepting'of course for the pivot post 5 in one tooth, and presents an extremely sanitary, strong, clean, neat, rugged and eflicient structure.

In Figs. 12 and 13 I have illustrated a slight modification of the invention, wherein each of the teeth and 26 are furnished substantially to size, it only requiring slight, if any, grinding to fit said teeth in a desired space. They may be furnished partially or completely baked, and if partially baked, could be stained by the dentist to the desired shade. Thereupon plastic porcelain 32 will be packed into retention cavities 31 in each tooth and smoothed off at the sides and backs. Thereupon the united teeth 25 and 26 would be baked, solidly unifying the teeth 25 and 26 into one solid homogeneous mass entirely of porcelain excepting for the metallic pivot post 28 extending through the vertical recess 27 in one of the teeth, the head 29 of said post having a bearing against the top of the retention cavity 31. Each of the teeth of this unit will have a full gingival margin 33, complete labial faces 36, lingual faces 34, and incisal edges 85. This form of the invention is obviously well within the range of the present application.

I believe that the teeth, and combinations of teeth above described, as well as the methods of manufacturing, assembling and uniting the same, are novel, and have therefore claimed the same broadly in the present application. 1

While I have necessarily described my present invention somewhat in detail,it will be appreciated that I may'vary the size, shape and arrangement of parts Within reasonably wide limits without departing from the spirit of the invention.

My invention is further described and defined in the form ofclaims as follows:

1. The improved method of constructing artificial teeth, which consists in providing a porcelain core having a predetermined contour, applying a matrix over said core, building on said matrix a shell of plastic porcelain, providing a tooth adapted to adjoin said first tooth and having a retention cavity therein, extending the mass of plastic porcelain of which said shell is composed into said retention cavity, removing said matrix, shell and adjoining tooth, baking the same, removing the matrix from the shell and then adhesively uniting the baked shell to said core.

2. The method of constructing a denture which consists in providing a tooth core and disposing a recessed tooth in a desired posi- This provides a denture contion at the side of said core, building a shell of plastic ceramic material on paid core and extending a part of said plastic material into the recess in said tooth, allowing the ceramic material to harden, removing the shell from the core with the tooth attached to said shell, baking the shell and the tooth, and thereafter adhesively applying the shell to the core.

3. The method of constructing an artificial pivot tooth which consists in placing a mass of plastic ceramic material over a pivot pin to provide a core, molding said core to closely simulate a natural tooth root in condition to receive a jacket crown, baking the same, ap-' plying a matrix over the core, building a shell of plastic ceramic material over the matrix, carving the shell to simulate a natural tooth, removing the shell with the matrix therein from the core, baking the shell with the matrix therein, removing the matrix from the shell, and applying the shell to the core.

4. An artificial pivot tooth comprising a core composed of a pivot pin and a body of ceramic material baked thereon, said body of ceramic material being shaped to closely simulate a natural tooth root in condition to receive a jacket crown and being inclusive of gingival and outer end portions, the latter of which is of less sectional area than the former whereby a shoulder is formed at the junction of said portions, the said gingival end portion being inclusive of labial and lingual faces, and ajacket crown of baked ceramic material to be applied over the outer end portion of said core body and to abut said shoulder, thereby to cooperate with said core to complete the tooth, the labial and lingual faces of said crown being adapted to form in efiect flush continuations or" the labial and lingual face portions, respectively, of the gingival end of the core body when said crown is operatively applied to the core.

In testimony whereof, I have signed my name to this specification;

CARLIN A. "WALSH. 

